2.0 Analysis 2.1 The Engine The No. 1 bearing failed as a result of separator and/or roller wear. However, the reason for the failure could not be established because of the extensive mechanical damage. 2.2 Manuals and Pilot Training The engine manufacturer's O M manual contains specific instructions on the maintenance actions required following the illumination of an engine chip light. It also contains information that allows personnel to make a correct assessment of the engine's continued airworthiness. The above information is available to maintenance personnel but is not readily available to flight crew. The company's FOM, issued to flight crew, did not contain any information on the required maintenance procedure for inspecting chip detectors that would assist flight crew in correctly assessing engine airworthiness. Pilots employed by the company have the authority to check chip detectors. Although they had apparently acquired, through informal discussions with maintenance personnel, a good understanding as to what are and what are not considered acceptable amounts of magnetic particles found on chip detectors, pilots do not receive the training that would allow them to correctly assess engine airworthiness when inspecting chip detectors. In this occurrence, the pilot carried out a precautionary landing following an engine chip light indication. This was the second engine chip light indication in less than eight flight hours and, according to the manufacturer's O M manual, the engine was not airworthy and should have been removed from service. However, because the pilot was not aware of the significance of recurring chip light indications and the required maintenance actions, the pilot did not perform a 30-minute ground run and incorrectly assessed the engine as airworthy. As a result, the No. 1 bearing failed and the engine stopped two minutes after the pilot took off to continue the flight. 2.3 Flight Manual - Chip Light Emergencies There is a discrepancy between the flight manual for the 206L and the flight manuals for other Bell 206 series helicopters in that a lower level of urgency for response to chip light indications is assigned for the 206L. Since the 206L shares similar components with other Bell 206 series helicopters and the consequences of an in-flight failure are the same, the less urgent response of landing as soon as practical seems inappropriate for 206L chip light indications. 3.0 Conclusions 3.1 Findings An in-flight engine stoppage occurred as a result of the failure of the compressor No. 1 bearing. The No. 1 bearing failed as a result of separator and/or roller wear. However, no metallurgical cause for the failure could be established because of the extensive mechanical damage. The pilot incorrectly assessed the engine as airworthy following a second engine chip light in less than eight operating hours, and took off to continue his flight. The pilot had not been briefed on the significance of recurring chip light indications or of the requirement to perform a 30-minute ground run following inspection of a chip detector. The company flight operations manual did not contain any guidance for pilots on checking chip detectors and making an assessment as to the engine's airworthiness. The pilot had not received any formal training on the checking of chip detectors as per the requirement in the company's maintenance control manual. The 206L flight manual indicates a lesser degree of urgency for response to chip light indications than do the manuals for other models of the Bell 206 series helicopter. 3.2 Causes The pilot incorrectly assessed the engine as airworthy and took off to continue the flight. The engine stopped two minutes after take-off when the No. 1 bearing failed as a result of separator and/or roller wear. The reason for the failure of the No. 1 bearing could not be determined. Contributing to this occurrence was the lack of adequate training for pilots on checking chip detectors and the absence of any guidance on inspecting and assessing chip detectors in the flight operations manual. 4.0 Safety Action 4.1 Action Taken 4.1.1 Operator Action Subsequent to the occurrence, the operator expanded its ground training syllabus to include more detailed instructions on the checking of chip detectors. The operator has also indicated that the company flight operations manual will be amended to provide guidance and a field reference for pilots on the checking of chip detectors. 4.1.2 Manufacturer Action The manufacturer is in the process of revising the 206L flight manual; the manual's procedural action for chip light emergencies will be amended from land as soon as practical to land as soon as possible. This revision is expected to be completed and distributed to 206L operators in the summer of 1995. 4.1.3 Regulatory Action In response to a TSB Advisory letter, Transport Canada indicated that regional inspectors have been advised to evaluate the training procedures in operators' maintenance control manuals and, during audits, to ensure that procedures are being followed. Transport Canada has also indicated that Airworthiness Manual Chapter 575 will be amended to the effect that personnel will be trained to check chip detectors and, where applicable, assess the airworthiness of the aircraft upon completion of the task.